In principle, instruments for closing and severing blood vessels have been known. One example can be learned from publication DE 602 26 015 T2.
Such instruments comprise an elongated shaft with a tool having two branches for clamping off a blood vessel, said tool being arranged on the distal end of said instrument. In addition, a knife that can be slid back and forth in longitudinal direction is arranged there in order to be able to sever a grasped and coagulated vessel. A handle with actuating means is provided on the proximal end of the shaft, by means of which the branches can be closed and the knife actuated. The branches are configured as electrodes in order to be able to heat the vessel clamped between them and to be able to fuse the vessel walls by coagulation.
When blood vessels are being severed it must be ensured that the ends of the severed vessel remain reliably closed. To accomplish this, additional requirements must be satisfied. For example, damage of the surrounding tissue is to be avoided. Closure of the vessel should be achievable largely independently of the size of the vessel and of the thickness of the vessel walls. In doing so, the confined space conditions must also be taken into consideration, said conditions requiring attention at the latest when the instrument is to be endoscopically or laparoscopically inserted.
Considering this, it is the object of the invention to provide an instrument for fusing and severing vessels, said instrument allowing the high-quality closing and severing of vessels.